Saw sharpening device



Dec- 5, 949 c. G. wAHLsTRoM 2,490,244

SAW SHARPENING DEVICE Filed Nov. 25, 1948 y I 2 sheets-sheet 1 43 E752, M M fw u N i 5 46mm' r,

f 6P M q 64 50 ,M 323? :56,- 66 -g- 5,. L, /55 J7 I. 1-- 51E-- FJ- Dec. 6, 1949 C. G, WAHLSTROM 2,490.244

SAW SHARPENING DEVICE Filed NOV. 23, 1948 2 Sheets-Sheet 2 j?? 4 f M@ gmc/Wto@ Patented Dec. 6, 1949 UNITE-D STATES PAT am or F l CE.

SAW SHARPENINGrDEVICE` r Charles G; Wahlstrom, Redwood City, Calif.

Applieation'lNovember 23, 1948; Serial No; 61,597

5-v Claims.

rLhis invention relatesitowsaw: Sharpeners and it consists inA they contructions, arrangementsv and combinations herein described and claimed.

-Itsis a particular object'off the invention to provide animproved and simpliiiedfconstructionrover thatv shownand described ini my United` States patent, issued- September 23, 1947;. Number 2,427,754, and particularly with respectto movementof'the'device alongthe teeth of asaw blade being,` sharpened;`

More-particularly it isfan object of the invention. to provide a sharpening: device for saws wherein abase member is employed having a longitudinal slot for-receptiony of a saw; aV motor, amount therefor, and anemery wheelbeing os'- cil-latably` mounted thereon; therefbeing a pair of slide members within-opposed walls of the longitudinal slot, the slide members having lugs for engagingteeth. of thesaw andfurther having operative connection with. the motor mount soL as to reciprocate the slidesfa-lternately uponoscilla-A tion of the motor and mount and thereby pro'- gressively advancing the Sharpener alongthe StW.A

It is a "still further object of the invention to provide a-novel cam actuating means between the basel and the motor to eiiectoscillation of the motor under rotation of the emery disk.

A further object of the invention is the provision of adjusting means whereby the device'mayo be'quickly set to sharpencourse or iinetooth saws, as well as rip'or crossfcutfsaws.

A still further objectofthe invention is the provision of meansbetween motor and the base whereby the former may be longitudinally adjusted with respect-tothe latter so that the emery disku be adjusted to the teethY of a saw.

Additionalv objects, advantages and features of the invention will be apparent from the following description considered in conjunctionV with the accompanying drawings, wherein:

- Figure 1 is aside elevationIk of the sharpening: device mountedupona saw, with the front clamp removed;

Figure 2 is a top plan View thereof indicating, by dotted lines, the oscillating motions of. the Sharpener;

Figure 3 is a cross section on` the line 3-3 of Figure 1;

Figure' 3d is I across' section of` a guide: employed' when: sharpening teethA of cross' cut saw;

Figure 4 is a reduced side elevation of the sharp= enin'g'devi'ce; illustrating themanner of securing ar saw in operative'engagement withtha sharpen-r ing device; f

Figure 5- isl an enlarged crossy section onthe line 5-5 of Figure 4; o

Figure 6 is an enlarged cross section onthe line; 6-6 of'Figure 4;

Figure-7 is an enlarged cross sectionalview on. the line l-T of Figure 4, illustratingthe drive for the emery disk and clamping meansrfor se-A curingY the saw imposition;

Figure 8 is a top plan view partly in section illustrating, by dotted lines, the movement of'the' motor mount to eiiectv alternate engagementof saw teethto motivate the Sharpener longitudinal-4 lyy ofthe saw.

Figure 9 is` a fragmentaryperspectve View of: one of4 the saw teeth engaging members.

There is illustratedv a portion of a work" bench or other suitable support IllV upon which there is' securedla clamp generally indicated at II'. The' clamp comprises a iixed jaw l2 and a movable jaw I3', the latter being drawn against the formen by means of bolts I4 for the purpose of rigidly securing a saw blade therebetween, the bolts be ing spaced atr points beyond the, extremities of' the saw blade, as clearly shown in-Figure 4. The` jaws I2v and i3 are rabbetedy upon their upper faces forming opposed channels I5, which func tion. for support' of the sharpening. device nowv to be described.. i

The Sharpening device, generally indicated' by the reference character IG, comprises a base mem-l ber I'I consisting. of ar pair of angle iron mem-f ber's I8 and i9, each having a lateral flange 2 0 adapted to rest upon the jaws I2 -and I3 of the' clamp with angle portions ZI arranged in paral-4 lel spaced relation and positioned within the' channel l5Y ofthe clamp. Thelateral angesZQ of angle iron members I8 and It) are cut awayias' indicated at 22 leaving only the angle portions 2i The angle irons I8 and I S function' as a guide' for a saw blade and by removing, the lateral flanges a path for an emery wheel is provided thereacross. inwardly of the rear en'd'cf each of the angle irons i8 and i9 the flanges 20 are formed with a owered surface 23 for a purpose presentlyto be described.

A plate 24, the same length as the angle irons', is secured to the flanges of the angle iron meniber's t`o` effecttheir securement' together andfat the portion where the flanges 2t haveA beenv moved', the plate is slotted as at'25f andi'o'rmed with depressed portion 2S so as t'o align l'aiiges permitting rotation o'f an' eineryacros'sf depressed portion ofthe plate; i "1 It will' bei noted-that theT a'ri'gl'e porti'ds'i 21' form? a parallel Yguide' Way, and within' th-fgd' l 3 way thus formed, a pair of saw tooth engaging members 21 are reciprocably mounted, one being positioned at respective sides of the angle portions as clearly shown in Figures and 6 of the drawings. The construction of the members :21 is identical, and as clearly shown in Figure 9 of the drawings, comprises a metallic plate 28 of elongated form, one end of which is provided with right angularly disposed horizontal ear 29 having an open elongated slot 30. Intermediate of the length of the plate an upstanding tongue 3| is formed and a similar tongue 32 is provided at the extremity of the plate. As best seen from Figure 8, the members 21 are arranged in parallel relation upon opposite sides of the saw blade with the ears 29 positioned in the low or depressed portions 23 of respective angle irons I8 and I9. Each of the tongues 3| and 32 are formed with a right angular tooth engaging lug 33 and 34. The

tongues are spaced two inches apart, so that they i will be operative upon any saw, regardless of the number of teeth. A flat leaf spring 35 is secured upon the plate 24 as at 36, the spring being longitudinally split to denne separate leaves 31 adapted to -rest upon respective tongues 32, and thus ten- .I

The plate 24 has an upstanding pivot 38 for I o'sclllatingly mounting a yoke 39, the latter having upright apertured ears 40 for mounting of the z notor unit, presently to be described. The plate 24 is formed with a slot 4| at respective sides ofthe pin 38 and the base of the yoke is similarly slotted as at 42. An actuator 43 is secured in each slot of the base of the yoke 39, here shown as a bolt 44, the head 44' of which occupies a position within respective slots 30 of the plate members 21. The head 44' has flat portions 43 disposed in the slot 4| for maintaining the bolt against rotation. The actuators 43 are adjustable along the length of the slots 4| and 4.2 by loosening the nut of the bolt to vary the length of travel of the members 21 to accommodate different sizes of saw teeth. Obviously, instead of the slots 4|, a pair of spaced openings may be employed for securement of the actuators 43 in desired positions.

An electric motor 45 is employed consisting of 'r a cylindrical casing exteriorly threaded as at 46 and 41, and upon these threads there is engaged respective locking rings 48 adapted to bind upon acollar 49, the later having legs 50 for pivotal mounting in the ears 40 of the yoke. For obtaining vertical adjustment of the motor the legs 50 may be provided with two or more apertures 5| for receiving a machine bolt 5| and in order to adjust the motor horizontally with respect to the yoke, the collar is longitudinally slotted as at 52 and receives a machine screw 53 therethrough which is engaged in the motor casing. It will be understood that by loosening the screw I53 and adjusting the rings 48 as desired, the grinding disk 54 of the motor may be properly positioned with respect to teeth of a saw.

The motor includes a reduction gearing 55 havlng a driven shaft 56 the lower end of which has mounted thereon a cam 51 disposed between a pair of parallel upstanding plates 58 integral with the plate 24, the plates 58 extending in a plane longitudinally of the plate 24 and are of a length considerably greater than the diameter of the cam as best seen in Figure 1 of the drawings.

Intermediate of the yoke 39 and the grinding disk 54, a guide plate 59 is detachably mounted upon the plate 24 'and the angle iron members I8 and I9, by means of machine screws 60, the guide extending transversely threacross. As clearly shown in Figures 1, 4 and 9, the guide includes a forward horizontal extension 6| of substantial width and intermediate the length thereof, a downwardly disposed recess 62 is formed, the ref cess having rounded surfaces at the meeting sides of the horizontal extension.

Upon the underside of the motor 45 and positioned in the medial longitudinal axis thereof, there is mounted a vertically adjustable stud 63, in the present instance, the stud is exteriorly threaded and engaged in an interiorly threaded boss 64 iixed to the motor. A knurled nut 65 is rigid with the stud to effect adjustment of the stud. The lower end of the stud is of rounded formation for smoothly traversing the extension 6| as well as the recess 62, and in order to maintain the stud in engagement with the extension, a tension spring 53 .is connected between an eye 61 on the motor and a loop 68 on the base 24 (see Figures 1 and 4). A leaf spring 69 carried by the motor engages the periphery of the nut 65 for maintaining an adjustment of the stud. It will be apparent that by adjustment of the stud 63 upwardly or downwardly the motor will be raised or lowered, pivoting upon the bolts 5I and thus adjust the grinding disk 54 with respect to the teeth of a saw. The guide plate 59 is employed in conjunction with the sharpening of teeth of a rip cut saw, but when a cross cut saw is to be sharpened, the guide 59' shown in Figure 3a is substituted. In this instance, the extension 6| is formed with a pair of recesses 62 positioned to opposite sides of the longitudinal axis of the saw blade, and equally spaced therefrom.

For safety from contact with the grinding disk 54 during rotation, a shield 10 is mounted upon the forward end of motor housing.

The operation of the device will be substantially as follows: the proper guide 59 or 59 having been installed, depending upon whether a rip cut or a cross cut saw is to be sharpened, the saw being clamped between the jaws 2 and 3 by tightening the bolts |4. The sharpening device |6 is set within the rabbeted portions |5 of the clamp jaws, the angle irons 2| and tooth engaging members 21 being disposed upon respective sides of the saw blade S. The grinding disk 54 is then adjusted to the angle of the saw teeth, and when the motor is energized and manually guided, the grinding disk 54 will traverse and grind the engaged tooth, the disk having an angular cut transversely and arcuately of the saw blade as indicated by dotted lines in Figure 2. This movement of the motor and the grinding disk is effected by virtue of the rotation of the cam 51 and its contacting engagement with the upright plates 58, which, it will be recalled are integral with the plate 24, the yoke 39 oscillating upon the pin 38. Under oscillation of the yoke the heads 44 of the bolts 44 will impart alternate reciprocation of the actuators 43, and under such movement of the actuators, a vertical movement is imparted against the action of the springs 31, permitting the tongues 3| and 32 to engage between teeth of the saw, as best seen in Figure 1, and thereby advance the Sharpener along the edge vof the saw.

From the foregoing, it will be seen that I have provided a saw sharpening device which is automatic in operation and which may be readily adjusted to the sharpening of diierent size and kinds of teeth of saws.

While I have shown and described a preferred form of the device, this is by way of illustration only and I consider as my own all such modifications in construction as fairly fall within the scope of the appended claims.

I claim:

1. A saw Sharpener comprising an elongated base having a medial longitudinal channel to receive the blade of a saw, a Ipivot bolt mounted in said base and vertically disposed, a yoke oscillatably mounted on said bolt and including upright spaced arms, a motor having a grinding disk, pivotally mounted on said arms, a guide plate on the base in advance of the yoke, an adjustable stud on the bottom portion of the motor and having engagement with said guide plate for adjusting said grinding disk with respect to the teeth of the saw, means for oscillatingr said yoke and motor for moving the grinding disk transversely across and between a pair of teeth of the saw, and means alternately engageable with the teeth of the saw for advancing the base along the saw under oscillating movement of the motor.

l2. The structure of claim 1, wherein the motor is longitudinally adjustable with respect to said yoke, and means for securing the motor in an adjusted position.

3. The structure of claim 1, in which the casing of the motor is provided with spaced right and left hand screw threads, a collar between said screw threads, a locking ring on said screw threads adapted to engage said collar, said collar having a slot and a lock bolt disposed in said slot and threadably engaged in the casing of the motor.

4. A saw Sharpener comprising a base having a channel to receive the blade of a saw, an oscillatable yoke on the base, a motor carried by said yoke and inclduing a rotatable grinding disk, said motor having a vertically disposed driven shaft, a cam on said shaft, a pair of upright plate members in contacting engagement with said cam whereby rotation of the cam will oscillate said yoke and motor to eiect movement of said grinding disk transversely across and between a pair 6 of teeth of the saw, a saw tooth-engaging member reciprocably positioned in opposed sides of said channel, said saw tooth-engaging member having spaced tongues for engagement with a pair of teeth of a saw, said tooth engaging members each having a lateral horizontal slotted extension at one end positioned beneath said yoke and an actuator carried by said yoke at opposite side of the vertical axis of the yoke, said actuators having a portion disposed within respective slots of said extensions.

5. A saw Sharpener comprising a base having a channel t0 receive the blade of a saw, an oscillatable yoke on the base, a motor carried by said yoke and including a rotatable grinding disk, said motor having a vertically disposed driven shaft, a cam on said shaft, a pair of upright plate members in contacting engagement with said cam whereby rotation of the cam will oscillate said yoke and motor to eiect movement of said grinding disk transversely across and between a pair of teeth of the saw, a saw tooth-engaging member reciprocably positioned in opposed sides of said channel, said tooth-engaging member having spaced tongues for engagement with a pair of teeth of a saw, said tooth-engaging members each having a lateral horizontal slotted extension at one end positioned beneath said yoke, spring means carried by the base and disposed above and in bearing engagement with the other end of said tooth-engaging members, permitting a limited upward movement of said tooth-engaging members, and an actuator carried by said yoke at opposite sides of the vertical axis of the yoke, said actuators having a portion disposed within respective slots of said extensions.

CHARLES G. WAHLSTROM.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,298,002 Butters Mar. 25, 1919 2,427,754 Wahlstrom Sept. 23, 1947 2,434,691 Fields Jan. 20, 1948 

